TOKYO -- Japan's expanding investigation into alleged collusion between the Defense Ministry and contractors has led to the arrest of a former vice minister.

Wednesday's arrest of Takemasa Moriya related to inflated prices paid for aircraft engines used by the Japanese air force, the Financial Times reported. The report also said the ministry has a reputation for paying higher prices for equipment, partly because a high proportion is made in Japan.

Moriya had earlier admitted to being treated to hundreds of rounds of golf by Motonobu Miyazaki, a former executive of a defense trading house, but denied providing favors to Miyazaki's employer Yamada, the report said.

Miyazaki was arrested this month in an embezzlement case.

The Defense Ministry has come under a cloud because of the investigation. Japan's Prime Minister Yasuo Fukuda said the ministry needs to "work hard to regain public trust."

The Financial Times' report said Japan's opposition parties, which have been vetoing Fukuda's bills because of the scandal, also plans to question Finance Minister Fukushiro Nukaga, who had worked as a director in the Defense Ministry.